Lighting control system



July 5,' 1938. w. MCGRATH LIGHTNG CONTROL SYSTEM Filed .Aprilv 27, 193e RESERVOlR szw TME \N sEcoNDS PRESSURE N PIPES? 2 PRESSURE 1N PIPE 5l o numerable combinations of colors and intensities motors by control devices which may take the Patented July 5, i938 maar LHGHTHNG CONTRL SYSTEM William L. McGrath, Minneapolis, Minn., as-

signor to Minneapolis-Honeywell Regulator Company, Minneapolis, Minn., a corporation of Delaware v Application spin agisse, serial No. 76,534

n zsoiaims. (eins- 312) This invention relates to lighting control syspressure motor and single control'valve means ltems in general and more particularly to lightfor proportionately brightening the'lights. ing control systems for use in theaters, audi- Other objects and advantages will become aptoriums and the like. parent to those skilled in the art upon reference Present day theaters areequipped with various to the accompanying specification, claims and groups of lights for obtaining dinerent lighting drawing, in which drawing; effects on the stage and in the auditorium proper. Figure l diagrammatically illustrates my light- These groupsoi lights usually comprise ooting control system, and lights, border lights andiiood lights for the stage Figure 2 is a graph illustrating the theory of and dome lights, wall lights and alcove lights for the proportionate brightening and dimming porthe auditorium. Each group is generally provided tion of my invention. with a plurality of variously colored lights. The Referring now to Figure 1, a plurality of lightvarious lights of the various groups are usually ing loads are generally designated at ill, Il, l2, controlled by means of an ordinary resistance and i3. These lights may be locatedin any detype dimmer plate or by means of the more resired place. The lighting loads lo, ll, l2, and I3 cent core type reactors where the lighting load are controlled by lighting CODIOl dViCeS it, i5, is relatively great. I6, and il respectively. Although any type of Attemptsl have been made in the past to reV lighting control device maybeused,have shown, motely control the various lights of the various for purposes of illustration, aconventional dimgroups but these attempts have not been entirely mer plateV for this purpose. The lighting control successful. devices M, I5, I6, and il may be operated by .It is, therefore, the prime 'object of this invenpressure motors i8, I9, 2li, and 2l respectively, tion to control the various lights of the various 'the pressure motors being illustrated as expansigroups in a new and novel manner whereby inble bellows. The pressure motors it, i9. Eiland 2l are controlled by control valves 22, 23, 2li, and 25 respectively, whereby the pressure motors may be individually adjusted to any desired position. A control valve,generallylrindicated at r2li, is provided to cause simultaneous operation of all of the pressure motors whereby the light intensities of the lighting loads may be proportionately brightened. Another control valve, generally designated: at El, is provided for simultaneously operating all of the pressure motors to cause proportionate dimming of the lights. Air" under pressure is supplied to the control system from a reservoir 29. A compressor 3B supplies air to the reservoir 39 and maintains the pressure in the reservoir 29 substantially constant. For purposes of illustration, the pressure maintained in the reservoir is assumed to be substantially 20st. Line Wires leading from vsome source of power, not shown, are designated 32 and 33. The line wire 32 is connected by a wire 3 to lights 35 4forming the lighting load. Lights 35 are in turn connected by a wire 36 and a switch 3l to the slider 38 of the control devices. The slider 38 is A adapted to slide across a resistance 39 one end of which is connected by a wire 4D to the other linewire'SS. The slider 38 is connected by a link 43 to the pressure motors and upon ex pansion of the pressure motors, the sliderv 38 is rotated in a clockwise direction. A spring 'Ml is provided for normally urging the sliders 3B irl'v a counter-clockwise direction. The arrangeof. lights may be obtained and accurately controlled. i

In carrying out my invention, I contemplate locating the resistance type dimmer plates or the core type reactors adjacent the lights that they control,I operating these resistance type dimmer plates or core type reactors by power means, which may take the form of pressure motors operatively connected thereto, and controlling these pressure form of valves located on a conveniently located panel board.

An object of this invention is to provide a control system for controlling the intensities or colors of lights comprising a pressure operated motor operable to a plurality of positions and a remotely located valve for controlling vthe pressures delivered to the motor whereby the intensities or colors of the lights may be accurately controlled.

Another object of this invention is to provide a plurality oi control devices for controlling the intensities or colors of lights with a pressure motor `for each control device, valvedmeans associated with each control device for controlling the same and a single valve means for proportionately dimming the lights." j

Still'another object of this invention is to provide a lighting control system having a plurality of control devices with a pressure motor for each control device, control valvev means for each illumination to a minimum valuea lug 4I cartions thereof.

ried by slider 38 opens switch 31 whereby'the lights are extinguished.

The pressure motors I8, I9, 20, and 2I are connected to the valves 22, 23, 24, and 25 by means of pipes 46, 41, 48, and 49 respectively. The valves 22, 23, 24, and 25 are in turn connected to branch pipes 50 whichterminate in a vent header 5I, which is controlled by the valve 26 so that when the valve 26 is open the header 5I is vented to atmosphere and when the valve 26 is closed, venting of the header 5I is prevented. The compressor supplies compressed air to the reservoir 29 through a pipe 54 and compressed air is taken from the reservoir 29 through a pipe 25 andan orifice 56 and delivered into a supply header 51. The supply header 51 is connected bybranchpipes 58 through orifices 59 to the pipes 46, 41, 48, and 49. The supply header 51 is adapted to be vented through a vent pipe 6I controlled by the control valve, generally indicated at 21.

Each of the control valves is provided with a combined operating handle and pointer 64 for positioning the valves and for indicating the posi- Suitable indications may be provided to cooperate with the pointer .to indicate the positions of the valves. The indications of valves 22, 23, 24, and 25 are illustrated as indicating the percentage of maximum light intensities, while'the indications of the valves 26 and 21 indicate the positions of these valves. As shown by the designations `associated with each valve, the valve is open when the pointer is in the extreme left position and is closed when the pointer is in the extreme right position. With the various Valves in the positions shown in the drawing, the `vent valve 21 is closed, the vent valve 26 is open, the control valve 22 is threequarters open, the control valve 23 is half open, the control valve 24 is one-quarter open and the control valve 25 is closed. With these valve positions and with a 20# airpressure supply, the pressure in the supply header 51, and consequently the branch pipes 58, is 20#, the pressure in the vent header 5I is 0#, and the pressures in the pipes 46, 41, 48, and 49, and consequently the pressure motors I8, I9, 20, and 2| are 5#, 10i-",- 15#, and 20# respectively. With these pressures existing in these pipes and pressure motors, the lights l0, II, I2, and I3 are adjusted to 25%, 50%, '15% and 100% of their maximum light intensities.

Movement of any of the vvalves 22, 23, 24, and 25 from their respective positions shown in thedrawing will cause proportionate movement of y their associated pressure motors and consequent proportionate adjustment of the lighting loads controlled thereby. Specically, if thevalve 22 is moved from the three-quarter open position to half open position, the light intensities of the lights I6 will be increased from 25% to 50%. Therefore, I have provided -a control system wherein the lighting loads may be individually and independently adjusted as desired.

The above operation is predicated on the fact that the valve 26 is open andthe valve 21 is closed. Ifthe valve 26 is maintained open to maintain a pressure in the vent header 5I of substantially and if the valve 21 is moved from the closed position shown towards the open position, the pressure in the supply header 51 will decrease and when the valve has become fully open, the pressure in the supply he'ader 51 will be substantially zero., vAs pointed out above, there is an orice 59 between the branch supply pipes 58 and the pipes 46, 41, 48, and 49 and by reason of these orices, the pressures in the pipes 46, 41, 48, and 49 will be reduced at a rate proportionate to the decrease in pressure in the supply header 51..Specica1ly, as the pressure in the supply header 51 is reduced, to say 104i, the pressures in the pipes 46, 41, 48, and 49 will be reduced to 21/2#, 5#, '1l/2# and 10# respectively and when the pressure in the supply header 51 is reduced to Dit, the pressure in the pipes 46, 41, 48, and' 49 will be reducedto 0# and they will all be reduced to 0# at substantially the same time.

This mode of operation is graphically illustrated in Figure 2, wherein the solid lines I, 2, 3, and 4 designate the pressures in the pipes 46, 41, 48, and 49 respectively. From this graph it is seen that as the pressure in the supply header 51 is gradually decreased from 20# to 0# the pressures in the pipes 46 41, 48, and 49 are reduced to D# but at a different rate whereby they are all reduced to 0# at substantially the same time. Since the light intensities of the lights Ill, II, I2, and I3 are directly proportional to the pressures existing within the pipes 46, 41, 48, andl 49, the light intensities of these lights are proportionately dimmed so that they are all extinguished at substantially the same time. This fact is also illustrated in Figure 2 by the solid lines I, 2, 3, and 4 when taken in connection with the ordinates and abscissas designated time and percentage of illumination.'

Assume that the valves 22, 23, 24, and 25 are in the position shown in Figure 1, that valve 2,6 is open as in Figure 1, and that valve 21 is also open, therefore the pressures in the supply header 51 and in thevent header 5I are substantially 0#. The pressure motors I 8, I9, 20, and 2|K are contracted and the lights are all extinguished.

Movement of the valve 21 from this open position towards the closed position, shown in Figure 1, gradually increases the pressure in the supply header 51 and the pressures in the pipes 46, 41, 48, and 49 will be gradually increased at a rate dependent upon the positions, of the valves 22, 23, 24, and 25. When the valve 21 is fully closed,

vthe pressures in the pipes 46, 41, 48, and 49 will arrive at pressure values of 101i', 15# and-20# respectively at substantially the same time. Therefore, movement of the valve 21 from the open position to the closed position causes proportionate increasing of the pressures in the motors I8, I9, 20,and,2| to the pressures determined by the positions of their associated control valves, and consequently, the lights will be brightened vfrom an extinguished condition to a per cent of illumination determined by thepositions of their associated control valves.

From the above it is seen that I have not only provided a lighting control system where the lights may be individually adjusted but I have also provided a means whereby the lights may be pro- `portionately dimmed from any intensity to a given intensity and proportionately brightened from the given intensity to any selected intensities.

If the valve 21 is maintained in the closed position shown in Figure 1 so as to maintain substantially a 20# pressure in the supply header S'I and if the valve 26 is moved gradually from the open position to the closed position, the pressure in the vent header 5I is allowed to increase from 0# and when the valve 2G is entirely closed, the pressure in the vent header 5I will increase to substantially 204%. By reason of the maintenance of a pressure of 20# in the supply header 51 andby reason of the orifices .59, an increase in pressure in the vent header '5I causes a proportionate increase in the pressure inthe pipes 48, 4l, 4B, and 49 and when the pressure in the vent header 5I reaches 201i. the pressure in the pipes 40; '411, H8, and 49 will likewise reach 20#. Reference is again made to Figure 2 wherein these increases in pressure are 'designated by the dotted lines, the dotted lines I, 2, 3 and 4 representing the pressures in the pipes 16, lil, 40, and 49 respectively.v Since the pressures in these pipes all reach 20# at substantially the same time and in a proportionate manner and since the light` intensities of the lights are adjusted in amanner proportionate to, the pressures in their respective pipes, the light intensities are increased from Vthe values shown to 100% intensity and they all arrive at this 100% value at substantially the same time. Y

Assume that the valves 22, 23, 2t, and 25 are in the position shown in Figure 1, that the valve 2l! is closed as in Figure l, and that the valve 26 is closed. By reason of these valve positions, the pressures in the supply .header El and the vent header 5I are substantially 20# and the pressures in the pressure motors I8, I9, 20, and 2i are also substantially 20#. Therefore, the lights are maintained at 100% brilliancy. Movement of valve 26 from the closed position to the -open position in Figure 1 causes gradual reducing of the pressure4 in the vent header 5I from 20# to Dit, and consequently, the pressures in the pressure motors I0, I9, 2li, and 2| are proportionately reduced to pressure values corresponding to the adjustments of the valves 22,23, 24, and 25 respectively and the pressures in the various pressure motors will arrive at their reduced pressure values at substantially the same time. Therefore,

' the lights are dimmed from 100% intensity to that intensity determined by their associated vcontrol valves and the lights will all arrive at the of the lights from that predetermined other value to the selected values.

In Figure 1, I have also illustrated another way of accomplishing proportional dimmi-ng instead of that outlined above. This other manner contemplatesthe use of a valve in the supply header 51 and also the use of orifice vents 61 in the pipes 4G, 41., 4I, and 40. The valve controlsdirectly the pressure in the supply header S'I.A As the valve 66 is moved from the open position to the closed position, the pressure in the 'supply header 51 is allowed to decrease byreason of the vents I1. Due to the oriilces Il the pressures in the pipes .46, 4l, 48. and 4! decrease at a rate proportionate to the rate of .decrease of pressure in the supply header l1 which gives truepropor-` tional dimming of the lights and the speelde manner in which this is accomplished is graphically illustrated' in Figure 2. K

It is to .be understood that the above exemplification of my invention is for purposesfof illustration only and not for purposes of limitation, also the various pressures utilized in connection with the description of my invention may be varied at will to arrive at the desired mode of operation. Other forms of my invention may become obvious to those skilled in the art and consequently this invention is to be limited only by said regulating means, means for biasing the pressure motor and the` regulating means in one direction, a source of air under pressure, a vent for said pressure motor, and valve means controlling the air pressure in said pressure motor, the air under pressure acting against said biasing means whereby the lighting eiect is controlled in accordance with the positions of said valve means.

2. In a lighting control system, the combination of lighting means for giving a desired lighting effect, regulating means in control of said lighting means, a pressure motor for positioning said regulating means, means for biasing the pressure motor and the regulating means in one direction, a source of air under pressure connected to said motor, the air under pressure acting 4 against said biasing means, a vent for said motor, and valve means for controlling said vent whereby the lighting effect is controlled in accordance with the position of said valve means.

3. In a lighting control system, the combination of lighting means for giving a desired lighting effect, regulating Vmeans in control of said lighting means, a pressure motor vfor positioning said regulating means, means for biasing the pressure motor and the regulating means in one direction, a source of `air under pressure connected to said motor, 'the air under pressure acting against said biasing means, an orifice in said connection, a vent for said motor, and valve means for controlling said vent whereby the lighting effect is controlled inaccordance with the position of said valve means. j

4. In a lighting control system, the combination of lighting means for giving a desired lighting effect, regulating means in control of said lighting means, a pressure motor for positioning said regulating means, means for biasing the pressure motor and the regulating means .in one direction, a source of air under pressure, a vent for said pressure motor, valve means controlling the air pressure inv said pressure motor, the air under pressure acting against said biasing means whereby the lighting eiect is controlled in accordance with the positions of said valve means,

and other valve means controlling` the supply of air pressure to said pressure motor.

5.-In a lighting control system, the combination of lighting means for givinga desired lighting eiect, regulating means in control of said lighting means, a pressure motor for positioning said regulating means, means for biasing the pressure motor-and the regulating means in one direction, a source of air under pressure, a connection between said source of pressure and said motor, the air under pressure acting against said biasing means, a vent for said motor, valve means l said regulatlngmeans, means'for biasing the pressure motor and the regulating means inK one direction, a source ci! air underwpressure connected to said motor, the air under pressure actlng against saidbiasing means, a vent for said 15. motor,` valve means for controlling said vent whereby the lighting eiect is controlled in accordance with the position of said valve means, and other valve means associated with said vent for additionally controlling the venting of said 20 motor.

'7. In a lighting control system, the combination of lighting means for giving a desired lightingeiect, regulating means in control of said 'lighting means, a pressure motor for positioning 25 said regulating means, means for biasing the pressure motor and the regulating means in one direction, a source of air .under pressure, a connection between the source of pressure and said motor, the air under pressure acting against said ai)V biasing means, a vent for said motor, valve means for controlling said vent whereby. the, lighting effect is controlled in accordancawith the position of said valve means, valve means associated with said connection for controlling the supply :5.0i air to saidpressure motor, and other valve e means associated with said vent for additionally f controlling the venting of said motor. l 8. In alighting Vcontrol system, the combination oi lighting means for giving a desired light- 4 0 ingelect, a plurality of regulating means in control of said lighting means, a pressure motor for each regulating means for positioning said regulating means, means for biasing each pressure ymotoriand regulating meansin one direction, a source of airunder pressure, a vent for each pressure motor, and vvalve means for each pressure motor for controlling the.air pressure in said motors, the air under pressure acting against said biasing means whereby each motor is posi- 50 tioned in accordance with the adjustment of its associated valve means to give a desired lighting eiect. y

9. In ya lighting control system, the combination of lighting means for giving a desired llght,

. 55 ing effect, a plurality of regulatlng'means in control of. said lighting means, a pressurekmoto'r for each regulatingl means for positioning said regulating means, means for biasing each pressure motor and regulatingfmeans in one direction, a

' 00 source of air under pressure, a vent for each -pressure motor, valve means for each pressure motor for controlling the air pressure in said-motors,A

the-air pressure acting ag nst said biasing means whereby each m'otor is positioned in accordance,

65 with the adjustment of its associated valve means to give la desired lighting eilect, and other valve V means ln control of the supply .of co ressedair to said motors to cause proportiona operation of said motors whereby the lighting efiect is pro- 7o 1 portionately varied;y l

1U.y In a lighting controlsystem, the combination 6I .lighting means for giving a desired lighting effect, a plurality of regulating means in control of said lighting means, a 'pressure motor for 75 yeach regulating means for positioning. said regul r i lating/means, a soumeof air under pressure, a

supply header connected .to said source of air under pressure, connections between said supply header and said pressure motors, a vent header,

' connections between said vent header and said 5 pressure motors, and valve means ineach ci said last mentioned connections to variably vent each of said motors whereby a desired lighting. eiIect ls obtained.

lating means, a source of air under pressure, a l' supply header connected to said source of air under pressure, connections between said supply header and said pressure motors, a vent header, connections between said vent header and said pressure motors, valve means in each of said last mentioned connections to variably vent each of said motors whereby a desired lighting eiect is obtained, and valve means ln control of the supply oi air to said Isupply header to variably position all oi said motors whereby lighting eect isfproportionately varied.V

l2. In a ligliting control system, the combination oi lighting means for giving a desired light- ,ing effect, a plurality oi regulating means in control of said lighting means, a pressure motor for. each regulating means for positioning said regulating means, a source of airA under pressure, 'a supply header connected to said source ci air under pressure, connections between said supply header and said pressure motors, a vent header, connections between saidzvent header and said y pressure motors, valve means in each of said last vmenticned-cdnnections to variably vent each of saidmotors whereby a desired lighting efiect is obtained, and valve means in control of said vent header to variably -positlon all o! said motors whereby the lighting eiIect is4 proportionately latlng. means, a source of air under pressure, a

spply header connected to said source of air 50 under pressure,` connections between said supply header and saidpressure motors, a vent header,

connections betweenv said vent header and saidv pressure motors, valve means in each of said last mentioned connections to variably vent each of said motors whereby a desired lighting effect isobtalned, and valve means in control o1 said supply header and ln control of said vent header to variably position all of said Amotors whereby) the lighting eiiect is proportionately varied.,

14. In a lighting control system, the combination of lighting means for giving a desired light- `ing effect, arplurality of regulating means in control of said lighting means, a pressure motor for each regulating means for positioning said regulating means, a source oi air under pressure, 'a supply header connected to said source of air under pressure, connections between said supply header and said pressure motors, a vent header,

connections between said vent header *and said pressure 4motors, valve means in each ci said last mentioned connections to variably vent each of said motors whereby a desiredy lighting eilect isl obtained, a vent .for said supply header, and

valve means in control cit-said vent to variably 'Il position' all of said motorswhereby the lighting effect is proportionately varied.

, 15. In a lighting control system, the combinationof lighting means for giving a desired lighting eect, a plurality of `regulating means in control of said lighting means, a pressure motor for each regulating means for positioning said of said vents to varlably position all of said motors whereby the lighting effect is proportionately varied.

16. In a control system, the combination of a 4plurality of pressure motors, a source of fluid under pressure, a supply header connected to said source, connections between said supply header and each o1 `said motors, a vent header, connec- 17. In a control system, the combination of a t plurality of pressure motors, a source of fluid underpressure, a supply ,header connected to said source, connections Vbetween said Supply header and each of said motors, a vent header, connections between said vent header and each of said motors, valve means in said last mentioned connections toadjust-.ably position said motors, a vent for said vent header, valve meanshin control of said vent, valve means in control ofthe supply' of. iiuid to said supply header, and orifice vent means for said motors.

18. In a control system, the combination of a plurality of pressure motors, a source o1' uid under pressure, a supply header connected to said source, a vent header, connections between said supply header, each of said motorsand said vent header, valve means for each motor in said connections to adjustably posltion'each motor in accordance with the adjustment of its associated valve means, and valve means in control of said vent header for additionally4 controlling the positionsV of all of saidmotors.. 4 ,i

19.In a control systemthe combinationv o! a plurality or pressure motors, a! source of uld under pressureya supply header connected to said source, a vent header, connections between said supply header, each of said motors and said vent header, valve means for each motor in said connections to adjustably position each motor in accordance with the-adjustment of its associated valvemeans, and valve means in control of said supply header for additionally controlling the positions of all of ysaid motors.

'20. In a control system, the combination of a plurality of pressure motors, a source of fluid under pressure, a supply header connected to .said source, a vent header, connections between said supply header, each of said motors and said vent header, valve means for each motor in said connections to. adjustably position each motor in accordance with the adjustment of its associated valve means, valve means in control of said vent header for additionally controllingthe positions of all of said motors, and valve means in control of said supply header for additionally controlling the positions of all of said motors.

2l. In a control system, the combination of a plurality of pressure motors, means for supplying actuating fluid to each of said pressure motors and venting actuating fluid therefrom, valve means for s aid means and associated with each pressure motor for controlling the pressure therein whereby each pressure motor may be positioned in accordance with the adjustment of its associated valve means, and valve means for controlling the venting' of the` actuating uid from all of the pressure motors.

22. In a control system; the combination of a plurality of pressure motors, means for supplying actuating iiuid to each of said pressure motors, and 'venting actuating fluid therefrom, valve means for said means and associated with each pressure motor for controlling the pressure therein whereby each pressure motor may be positioned in accordance with the adjustment of .its associated valve means, and valve means for venting thevactuating'uid from all of the pressure motors.'

23. In a control system, the combination of a plurality of pressure motors, means for supplying actuating uid to each of said pressure motors and `venting actuating uid therefrom', valve means for said means and associated withr each pressure motor for controlling the p 'ure thereln whereby each pressure motor tioned in accordance with the adjustment of'its associated valve means, and valve means for preventingventing of the actuating fluid from all of the pressure motors.

ay be posi- 

